1. Field
This disclosure generally relates to systems and devices for isothermal biochemical reactions, for example nucleic acid amplification or cell growth, and/or analytic equipment to analyze the products or results of such biochemical reactions.
2. Description of the Related Art
There are a number of known techniques to perform biochemical reactions, for example to amplify nucleic acids such as DNA and RNA.
One of the primary existing techniques is polymerase chain reaction (PCR) method, such as that described in U.S. Pat. Nos. 4,683,195; 4,683,202; and 4,800,159. Another existing technique is reverse transcription (RT) PCR. Other techniques include ligase chain reaction (LCR) and transcription-based amplification system (TAS).
These techniques each require repeating a set of reactions for each sample at two or more distinctly different temperatures, commonly known as thermal cycling. These techniques typically require strict control over a wide range of temperatures. There are a number of thermal cycling devices on the market. It is commercially desirable that these thermal cycling devices be capable of rapidly adjusting between the desired reaction temperatures in order to increase the number of reactions per unit of time, thereby increasing throughput and reducing costs associated with operation of such thermal cycling devices. The need to strictly control temperature over a wide range with a fast response time causes these thermal cycling devices to be expensive, for example costing between $40,000 and $60,000. Due to these requirements, thermally cycling device are also large, and are not suitable to being provided in portable or handheld forms.
Amplification techniques that avoid thermal cycling are becoming more popular. For example, strand displacement amplification (SDA) such as described in Japanese Examined Patent Application No. JP-B7-114718 and various modifications of SDA such as described in U.S. Pat. No. 5,824,517 and International Patent Application Nos. WO99/09211; WO95/25180 and WO99/49081. Also for example, self-sustained replication (3SR), nucleic acid sequence based amplification (NASBA) such as described in Japanese Patent No. 2650159, transcription mediated amplification (TMA), and Q beta replicase method such as described in Japanese Patent No. 2710159. Further examples include loop mediated isothermal amplification (LAMP) such as described in WO00/28082 and exponential amplification reaction (EXPAR) such as described in U.S. Patent Application Publication Nos. 2003/0082590, 20003/0104431; 2003/0138800 and 2003/0165911.
It is common to employ thermal cycling devices to perform isothermal biochemical reactions, even though thermal cycling is not required for such isothermal processes. However, as noted above, devices capable of thermal cycling are prohibitively expensive. Such devices are also typically large, and not portable or suitable to handheld formats.
A number of analytic devices exist to analyze samples that have been subjected to biochemical reactions such as nucleic acid amplification. Such analytic devices typically employ laser or monochromator based excitation systems. Such devices are typically large and expensive.
Commercial acceptance of alternative amplification techniques is dependent on a variety of factors, such as the cost of suitable devices, speed of operation and effectiveness in performing amplification and/or analysis. Commercial acceptance may also depend on the portability of isothermal reaction and/or analysis devices. Commercial acceptance may additionally, or alternatively be dependent on the ability for an isothermal reaction and/or analysis device to work with existing sample holders, avoiding the need to stock multiple types of sample holders or the need to replace existing stocks of sample holders. Therefore, it may be desirable to have novel biochemical reaction and/or analysis devices. The present disclosure is directed to overcoming one or more of the shortcomings set forth above, and providing further related advantages.